EXTRACTS FROM MEMBERS’ NOTE-BOOK 153 
Birds Singing at Night 
Have any members heard birds singing or warbling at 
night ? On four different occasions I have heard Pycnonatus 
layardi (yellow- vented bulbul), warbling long after darkness 
had set in. 
Are there any members interested in bird photography ? 
V. G. L. VAN SOMEREN. 
Mimicry 
I observed in April 1912 a case of mimicry which is 
interesting, but as I was going on leave in a day or two I could 
not complete the observation. 
On an orange tree were two or three green caterpillars, 
apparently of the common hawk species, green, with the hump 
over the head and tail. I approached to take the specimens, 
when one opened suddenly a slit below the apparent mouth 
in the ordinary caterpillar and shot out a reddish forked 
tongue. It gave me the idea at once of mimicry of the snake 
in self-defence against a bird. 
W. M. Falloon, 
Longevity of Snails 
Can anyone give me any help towards settling the life of 
a snail here ? Is it a period of six or twelve or more months 
according to the bi-yearly fires ? 
It seems to me the shells hibernate twice during each dry 
weather and that most of the adult ones are burnt. 
W. Marcus Falloon. 
Yellow Copepoda 
In September 1910 I collected from the water-holes of 
Boma Uponde (between Malindi and Fundi Isa) some small 
Crustacea (Copepoda, ? Cyclops ) but of a brilliant yellow colour. 
Two slides mounted in Canada balsam, October 10, 1910, have 
not yet lost in any way the natural yellow colour. 
